Telephonic receiver



(No Model.) I

C. CUTTRISS 81.- G. F. MILLIKEN.

, TELEPHONIG RECEIVER.

No. 256,795. PatentedApr. 18,1882.

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UNITED STATES PATENT OEErcE.

CHARLES GUTTRISS, OF DUXBURY, AND GEORGE F. MILLIKEN, OF BOSTON, y

MASSACHUSETTS, ASSIGNORS TO JAMES WENTVORTHBROWN AND HENRY D. HYDE, fBOTH OF BOSTON, -MASSAGHUSEITS.

TELEPHoNlC-RECEIVER.

SPECIFICATION forming part of Letters Patent No. 256,795, dated .April 18, 1882.

- y Application filed August S22, 1881. (No model.)

To all whom it may concern:

t Be it knowuthatwe,GHAR1.Es UUrrRIss, a subject ofthe Queen of Great Britain, and a resident of Duxbury, in the county of Plymouth and State of Massachusetts., and GEORGE F. MI'LLIKEN, a citizen of the United States, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have jointly invented a new and useful Improvement in Telephonie Receivers, of which the following is a specification.

Our invention relates to that class of telephonie receivers in which a resonant body is thrown into vibration by the action thereupon of electric undulatious or vibrations transmitted over a line from a distant station; and the particular object of the invention is to increase the loudness and clearncss of the sounds which are produced in the atmosphere by the movement ot' said resonant plate when so actuated.

Our invention consists chiey in a novel combination and arrangement ot' certain devices, whereby the mechanical vibrations produced by electric undulations are transmitted t0 the resonant plate of the receiver by the agency of friction.

In the accompanying drawings, Figure l is a side elevation, partly in section, ot our improved telephonic receiver. Fig. 2 is a front elevation with the ear-tube and outer portion of the case removed, and Fig. 3 is an enlarged view of certain parts shown iuFig. 1.

In the drawings, A represents a plate constructed of very thin brass or similar resilient metal, which is preferably in the form of a strip having a much greater length than breadth. This plate is secured at one of its ends, by means of a screw, a, or otherwise, to the support A', which is circular in form, and may be of wood, while its other end is loosely7 attached to the opposite side of the face ot' the support A bythe screws a', which pass through the slot a2 in said strip.

An annular ring, of wood or other suitable material, C, preferably of the same external diameter as the support A', is firmly clamped between said support and its cover D. The latter is perforated with a centra-l opening, into which is inserted a suitable car-trumpet,

E. The ring C and cover D, when tightly screwed or clamped together, support a resonant plate or membrane, B, a portion ot'which is also shown in Fig. 2. This plate is rigidly held in position by screws el d, which extend through the support D into the ring C. The resonant plate B is preferably constructed in a circular form, of thin metal or of a stretched membrane, and is capable of producing sonorous vibrations in the surrounding atmosphere. It is perforated with a small aperture, e, at or near its center, (see Fig. 3,) through which pass one or more thin but stiff wires, b b. These wires are soldered or otherwise iirmly attached to the -vibrating plate A, and when the latter is thrown into vibration, as hereinafter explained, they move to and fro in a horizontal direction through the aperture e in" the. resonant plate B, and at the same time, and by virtue of their resiliency, press against the edges of theaperture e in the plate. Thus the plate A, being thrown into vibration by an undulatory electric current, as hereinafter described, moves the wires (I d to and fro through theaperture in the plateB and against its edges. Il`he vibrations of the plate A are therefore exactly reproduced, but with less amplitude, by the resonant plate B, and the wires b b, by their frictional contact with said plate, are found to producemuchlouder sounds than those produced by a diaphragm directly actuated by an electro-magnet. The space intervening between the supports A and D has the effect of rc-enforeing the sounds produced by the plate B, and this, together with the action hereinbefore described, causes very loud and distinct sounds to proceed from the ear-piece E.

The apparatus which I prefer to employ for actuating the plate A and its attachments consists of a permanent magnet, F, of any suitable construction, which is secured to the support A by means of the clamping-pieces G, of which one is shown, another precisely similar one being placed on the other side of the magnet, and the two being held together by screws or bolts. The magnetF is preferably a compound magnet,built up of a number of independent plates separately magnetized and afterward united together. To one pole of the magnet F-for example, the north pole, n-is affixed orinserted a cylindrical pole-piece, P, preferably of soft iron,while to the south pole,s, is afxed another pole-piece, R,consist ing essentially of a hollow cylinder or ring provided with an angular projection, Z, by which it is attached (preferably by soldering) to the pole s of the magnet F. The diameter of the circular aperture within the ring is considerably greater than that of the cylindrical pole-piece l?, so that the former will encircle the latter when the parts have been placed in position, leaving an annular spacebetween the cylinder and the ring. By thus causing the actual south pole ot' the magnet F to completely encircle the cylinder which forms the north pole, nearly the whole of the magnetic energy is concentrated within a very narrow field between the poles.

I is the cylindrical coil or helix, of thin insulated copper wire, which is mounted upon and rmly attached to the center ot' the plate A, the axis ot' the coil being coincident with the axis ofthe cylindrical pole-piece l?. This coil isconstructcd of such external and internal diameter as to be capable of vibrating` to and fro in a direction parallel to its axis within the annular space left between the inner and outer pole-pieces, P and R. An undulatory current proceeding from a suitable transmitter enters at the bindingpost T, passes through the coil I by wire l, and returns by wire 2 and binding-post T to the ground or a return-wire, and thence to the generator. The current passing through the coil produces an alternate attraction and repulsion between it and the permalnent magnet and causes a to-and-fro vibratory motion ofthe coil, which is communicated to the plate A, upon which the coil is mounted, and thence by the Wires b b to the resonant plate B. The form of apparatus which we have described for actuating the plate A forms no part ofour invention, and is not hereinafter claimed, but is nevertheless the form which we prefer to, use in connection with our improved receiving apparatus. If desirable, however, anyother well-known form of actuating apparatus may be used. For instance, the plate A may be constructed of magnetic met-al and directly acted upon in the manner ot' an armature by an electro-magnet.

The organization hereinbeforc described, by means of the friction caused by the wires b I) moving in contact with the resonant plate B and the resonant chamber between the latter and the plate B, constitutes a telephone-receiver which is found to be capable of producing much louder and clearer articulate sounds than ispossble by telephones heretofore in use.

We claim as our joint inventionl. The combination, substantially as hereinbefore set forth, of a resonant plate, membrane,

or body, a device for communicating vibrations to the same by i'rictional contact therewith, and apparatus for actuating said device by the conversion ot' electrical undulations or vibrations into mechanical force.

2. The combination, substantially as hereinbefore set forth, of a resonant plate, membrane or body, one or more wires or rods extending perpendicularly through an aperture formed therein, and in frictionalcontact therewith, and an electric actuator for imparting longitudinal vibrations to said wires or rods, which vibrations are communicated to said resonant plate.

3. The combination, substantially as hereinbefore set forth, of a resonant plate or membrane, one or more wires or rodsv extending perpendicularly through an aperture'therein, and in frictional contact therewith, a vibratory plate supporting said` wires or rods, and an electric actuator for producing vibrations in said wires and plates.

t CHARLES CUTTRISS.'

GEORGE F. MILLIKEN.

Witnesses to C. C.:

J. C. ROBINSON, R. J. NEEDHAM.

Witnesses to G. F. M.: FISHER AMES, RoBT. J. TAYLOR. 

